1. Field of the invention
The present invention relates to a process for formation of a base, and more particularly to a process for formation of a base from a base precursor which is substantially neutral during the storage. The invention also relates to a light-sensitive material comprising a light-sensitive layer containing silver halide, reducing agent and polymerizable compound provided on a support.
2. Description of prior art
Bases are reagents widely used in various reactions (e.g., hydrolysis, polymerization, coloration, redox reaction, and neutralization). A base component is incorporated into many products such as developing solutions in silver salt photographic processes, heat-developable light-sensitive materials, adhesives, detergents, etc.
However, the bases (particularly strong bases) have a problem with respect to stability in that they absorb carbon dioxide from air and are then inactivated. Further, the strong bases, which are highly reactive, have much difficulty in storing them in contact with other component. Furthermore, it is possible that the bases have harmful infuence on the human body, for example, they irritate the skin. Therefore, when bases are dealt with, it is necessary to pay attention to the toxicity and the skin irritation.
Accordingly, the products containing a base component have problems in the stability of the bases, the preservability of other component in contact with the base and the handling characteristics.
In order to eliminate the above-mentioned problems, it is proposed in Japanese Patent Provisional Publication No. 59(1984)-180537 (corresponding to U.S. Pat. No. 4,560,763 and European Patent Publication No. 0123937B1) to use a base precursor having the below-mentioned formula (I) or (II) in place of the conventional bases. As described in the patent publication, the base precursor having the formula (I) or (II) is very stable at ordinary temperatures. The base precursor can be rapidly decomposed to release a base, when it is heated at a certain temperature. Therefore, the base precursors are suitably used in a heat-developable light-sensitive material.